The invention relates to a light detecting and direction determining device comprising several groups of light receiving elements.
The term light is herein understood to mean ultraviolet and infrared radiation as well as visible light. The radiation is originally coherent, that is the wave front from the light source has a high degree of correlation in time and space, which is the case for laser light.
Such a light detecting and direction determining device is described in GB-A-No. 2 112 244. The light receiving elements are here formed by one of the end surfaces of optical fibres (light guides). Each end surface of a fibre, which serves as a receiving element, normally covers a separate angular space while each fibre has a different length which is used to identify the angular space in question. During real operation conditions affected by air turbulence and so called "speckles" associated herewith, a device of the type described above has an insufficient performance, especially in the case of separate laser pulses.